1. Field of the Invention
The present invention relates generally to a device for transporting materials, and relates more specifically to a trailer to be towed behind a vehicle for transporting a pallet and the material disposed thereon.
2. Description of Related Art
A variety of materials are presently transported and stored on pallets. Typically, these pallets are of a standard construction having two flat wooden platforms with wooden spacers therebetween creating a gap of several inches, wherein the forks of a forklift may be inserted for lifting the pallet and any materials thereon. Presently, material on pallets typically is transported by loading a number of pallets onto a large flatbed truck using a forklift, driving the loaded truck to the point of destination, and unloading the palletized material by forklift at the destination. This method of transport is efficient for large numbers of pallets, but requires forklifts at both the point of origin and the delivery point, and a flatbed truck for transporting the palletized material. Because of the considerable expense involved, the transport of a single pallet of material is generally cost-prohibitive using presently existing transport methods. A variety of applications have been discovered wherein it would be desirable to transport a single pallet of material economically. For example, in the landscaping business, earthen sod is generally purchased by the pallet. Standard truck-and-forklift delivery methods are acceptable when the particular landscaping project requires a number of pallets of sod; however, many landscaping projects arise requiting only a single pallet of sod, or less.
Several devices are known to be capable of transporting a single pallet of material; however, for a variety of reasons existing prior art devices have been found to be less than entirely satisfactory. For example, U.S. Pat. No. 4,944,648 to Parr describes a trailer assembly with a load-carrying frame pivotally mounted for movement between an upright loading and unloading position, a first inclined towing position, and a second horizontal towing position. It has been found that because of the small radius of rotation in the shown mechanism, the load-carrying frame must be rotated through a fairly wide arc in order to lift the load above the ground a distance sufficient to comply with Department of Transportation ground clearance regulations (eleven (11) inches minimum). Thus, as the load-carrying frame of the '648 device is lifted from the ground, the load-carrying frame and the load move from an essentially horizontal orientation to an orientation which is so steeply inclined that many materials, such as sod, will not stay on the pallet.
Another device is shown by U.S. Pat. No. 4,666,359 to Parr which describes a towable dolly having a lifting platform pivotally connected behind its wheel assembly. It has been found that positioning the load carrying assembly behind the wheel assembly results in an unstable towing configuration wherein the weight of the load is not centered over the wheels or slightly in front of the wheels as is desired for a safe and stable towing configuration.
Thus, it can be seen that a need presently exists for a towing device capable of transporting a single pallet of material behind an automobile or light truck without the need for forklifts or a large flatbed truck. Additionally, there exists a need for a towing device capable of lifting a pallet of material a distance above the ground sufficient to comply with Department of Transportation ground clearance regulations without tilting the load so far beyond the horizontal position that the palletized material falls off of the pallet. Moreover, there exists a need for a device for towing a single pallet of material which allows the load to be centered over the wheels of the towing device or slightly forward of the wheels, such that the loaded device is stable when towed.
It is to the provision of a towing device capable of meeting these and other needs that the present invention is primarily directed.